Lathes are known for turning rotationally symmetrical elements such as bowls and spindles from a rectangular blank. Typically the workpiece is mounted between a headstock and a tailstock and rotated at high speed while a knife or knives are engaged with the rotating blank to cut and shave a desired profile into the blank. Lathes are typically used for turning wood blanks, but other materials such as metals and composite materials may be mounted and formed while turning on a lathe.
While some lathes have beds that can be raised or lowered or moved towards and away from a headstock, in general, conventional lathes have limited versatility. Indeed, it is difficult with conventional lathes to accommodate a particularly long blank, such as for a column, or a particularly wide blank, as may be provided when a bowl is to be turned. In addition, it would be desirable to provide a lathe which allows the operator to selectively lock the workpiece at any one of a plurality of incremental angular positions as may be required for surface finishing a workpiece that has been turned on the lathe.
Even further, conventional lathes tend to be boxy assemblies presenting monolithic rectangular headstocks and tailstocks which may hinder access to parts of the workpiece and/or may be uncomfortable to the operator, particularly if the operator leans on the headstock or tailstock during set-up or operation. Sharp corners may also cause minor but unpleasant injury. It would therefore be desirable to provide a more ergonomically shaped, smoothly contoured headstock and tailstock to minimize visual and physical obstructions and so as to be more comfortable in the event of operator contact. Ergonomically shaped and otherwise smoothly contoured assemblies are also highly desirable and attractive to consumers who, in general, find a modern, sleek and sophisticated appearance to be highly desirable.
It is an object of the invention to provide a versatile lathe that addresses the deficiencies of the conventional lathes noted above.
It is conventional to provide a tool rest that slidably engages a bedway and is selectively cam locked in position. Such conventional cam locks typically include an eccentric shaft received in the cylindrical bore of a piston disposed in the housing of the tool rest and a clamping plate provided below the bedway for being clamped against the bedway when the cam shaft is rotated. Such locking assemblies define clamping pressure at the locus of the locking plate and at the longitudinal ends of the eccentric shaft. This can lead to bowing of the cam shaft and the potential for an incomplete clamping of the tool rest to the bedway.
Thus, it is a further object of the invention to provide a locking assembly for locking components, such as a tool rest, to a bedway in a manner that eliminates shaft-flex.
Accordingly, the tool rest provided in accordance with a presently preferred embodiment of the invention has a unique sliding piston locking system that eliminates shaft-flex, thereby ensuring a creep-free positive lockdown, even under the heavy impacts of large diameter outboard turning.
Accordingly, in a first aspect of the invention, a lathe assembly is provided that comprises: a base unit having first and second longitudinal ends; a headstock assembly comprising a housing and a spindle shaft assembly extending therethrough and rotatably mounted thereto, the spindle shaft having a longitudinal axis; a first bedway defined on the base unit for selectively receiving at least one of a tailstock and a tool rest assembly, the first bedway generally extending from the headstock assembly toward the second end of the base unit, the first bedway having a longitudinal axis parallel to the longitudinal axis of the spindle; a shaft locking assembly secured to the spindle shaft for selectively locking the spindle shaft with respect to the housing at 90 degree intervals; and an indexing assembly for angularly positioning and holding the spindle shaft with respect to the housing at any one of a plurality of intervals intermediate the 90 degree intervals of the shaft locking assembly, the indexing assembly including an indexing component fixedly secured to the spindle shaft and an indexing pin mounted to the housing of the headstock assembly.
According to another aspect of the invention, a lathe assembly is provided that comprises: a base unit having first and second longitudinal ends, a headstock assembly provided adjacent the first longitudinal end of the base unit, the headstock assembly including a spindle housing having a spindle shaft extending therethrough, a first lathe bed assembly provided on the base unit and including a bedway extending longitudinally in a direction parallel to the longitudinal axis of the spindle for slidably receiving at least one of a tool rest and a tailstock; and a second lathe bed assembly detachably coupled to at least one of the first and second longitudinal ends of the base unit, the second bed assembly including a second bedway for selectively receiving at least one of a tailstock and a tool rest assembly.
According to yet another aspect of the invention, a lathe assembly is provided that comprises: a first base unit having first and second longitudinal ends and including a first lathe bed assembly having first and second longitudinal ends and a first bedway defined therein for slidably receiving at least one of a tool rest assembly and a tailstock assembly; a headstock assembly mounted to the base unit, the headstock assembly including a spindle housing portion having a spindle shaft rotatably disposed therein; a first tailstock assembly selectively slidably disposed in the first bedway, the first tailstock assembly including a quill housing portion having a quill assembly rotatably disposed therein and axially aligned with the spindle shaft of the headstock assembly; and a locking assembly for selectively locking the first tailstock assembly to the first bedway, wherein at least one of the quill housing portion of the first tailstock assembly and the spindle housing portion of the headstock assembly is generally elliptically shaped in longitudinal section and generally circularly shaped in transverse cross section so as to define a generally continuously curved outer peripheral surface.
According to yet another aspect of the invention, a tool rest assembly for a lathe apparatus having a lathe bed assembly is provided, the tool rest assembly comprising a tool support housing extending vertically from a tool rest main body, the tool rest main body comprising a tool rest housing and a locking assembly for selectively locking the tool rest housing to the lathe bed assembly, the locking assembly including a locking plate for engaging an undersurface of a bedway of the lathe bed assembly; a slider block seated and disposed within the tool rest housing, a non-circular locking shaft extending longitudinally of the housing and disposed through a bore in the slider block, and a locking piston vertically slidably disposed in the slider block, the locking piston having a bore for being aligned with the bore of the slider block to receiving the locking shaft and having a shaft for being detachably mounted to the locking plate, whereby rotation of the locking shaft about the longitudinal axis thereof lifts the locking piston and the locking plate mounted thereto while pressing the block so as to clamp the housing to a bedway between the slider block and the locking plate.